1. Field of Invention
The present invention relates to an image compression method with variable quantization parameters and variable coding parameters, and more particularly to an image compression method with variable quantization parameters which requires less memory space.
2. Related Art
A conventional encoder adopts a prediction method such as context modeling, which needs to at least buffer a whole row of pixels of an image so as to perform prediction in various modes. Therefore, the conventional encoder requires a large amount of storage space, resulting in an increased cost thereof. Furthermore, the conventional encoder must perform a compression test on each mode when making a selection from various modes, till the encoding result is in line with expectation. Therefore, the computation is complicated, and the encoder requires different time for each processing.
In addition, request of users for higher and higher image resolutions aggravates the burden on image compression. If a conventional compression method is adopted, once the image resolution is enhanced, the encoder needs to consume a larger amount of storage space to store a whole row of pixels in an image for image compression.